Continuing from a previous video, Sal takes the discussion of the focus and directrix of parabola further. Given the parabola, y=x2, he derives the focus and directrix by matching parts of the equation he found earlier. He then, comes up with a more general solution to finding the focus and directrix of any parabola. Parts of this video might be a bit complex for some listeners since he uses variable names that may different from those traditionally used in some textbooks. The end of the video, however, does wrap things up nicely with an intuitive solution for finding the focus and directrix for any parabola.